Many persons with neurological injuries require a wheelchair for mobility assistance. When such persons have severely weakened arms and hands, they often cannot move the wheelchairs by themselves. Therapeutic exercise following a neurological injury can not only improve arm and hand function but can further help prevent secondary complications such as contractures. If a person could regain enough arm movement, he or she may then be able to operate a wheelchair without, or with less, assistance.
There are various ways in which such therapeutic exercise can be performed. One option is active assistance exercise facilitated by a trained therapist. Active assistance requires that the patient actively contribute to the movement, an aspect of training that is important for motor learning and plasticity. Active assistance also enables patients with a high level of impairment to participate meaningfully in therapy by limiting frustration, increasing motivation, and promoting self-efficacy. Active assistance may also enhance sensory input that drives motor plasticity and can demonstrate correct movement patterns that enable better learning. While such active assistance provides many benefits, one-on-one sessions with a trained therapist are expensive and therefore out of reach to many individuals.
Because of the expense involved with using a therapist, there has been a surge in the development of devices that partially automate rehabilitation exercise. For example, robotic therapy devices have been designed to provide “assistance-as-needed” to arm movement, mimicking the clinical technique of active assisted exercise. While such robots enable a variety of forms of active assistance, they are also relatively expensive and often complex, making them impractical for widespread use. In addition, the viability of using devices that can actively apply large forces to limbs in minimally supervised environments, such as at home, is still unclear.
Persons with arm weakness can exercise their arms on their own without using a therapist or a robotic therapy device. However, if their arms are severely impaired, such exercise is difficult and compliance with autonomous exercise programs is low.
In view of the above discussion, it can be appreciated that it would be desirable to have a simple and inexpensive apparatus and method that enable an individual to exercise his or her arm for therapeutic purposes.